Former Goldman Sachs trader Fabrice Tourre, accused by regulators of defrauding investors of $1 billion in a 2007 toxic mortgage bond offering, is expected to take the stand today to clear his name.

“Fabulous Fab,” as he called himself in an email, will have some heavy lifting to do.

Over the last several days, witnesses have painted a rather dour picture of the 34-year-old Frenchman for the nine-person jury.

Former co-workers and an executive at a company that helped choose the securities for the so-called Abacus CDO said they were misled into thinking hedgie John Paulson was going to invest in the mortgage-backed security.

Instead, Paulson, who helped choose the mortgages for the CDO, bet against it. The CDO eventually collapsed and investors lost $1 billion.

Goldman settled with the Securities and Exchange Commission — paying a then-record $550 million fine — but Tourre is fighting the civil charge that he misled investors.

The SEC’s star witness, Laura Schwartz, a former executive ACA Management, the bond insurer helping to choose the securities, testified yesterday for more than four hours on the stand that she was lied to in the Abacus case.

She was led to believe that Paulson was a long investor, she told the Manhattan federal court jury.

“I had gone into the meeting assuming that they would be the equity investor in the transaction,” Schwartz testified.

Wearing a dark blazer, matching skirt, white blouse and pearl necklace, Schwartz said several times that no one at Goldman told her that Paulson was not an equity investor.

Schwartz, who left ACA in the fall of 2007, said her former firm worked only with Paulson’s former right-hand man, Paolo Pellegrini, in selecting the Abacus assets because she assumed the hedge fund was a long investor.

Her story is similar to that of ex-Goldman salesperson Gail Kreitman — a liaison between Goldman and ACA — who testified last week that she also was under the impression that Paulson was backing the deal.

However, Schwartz’s testimony fell short of directly accusing Tourre.

The former securities trader is one of the few insiders charged in the aftermath of the US housing collapse and, if found liable in the civil case, could become a poster child for Wall Street greed.